Manufacture of window envelopes



Feb. 9, 1937. v. E. HEYWOOD MANUFACTURE OF WINDOW ENVELOPES Filed June 27, 1934 5 Sheets-Sheet l m m m H m ZM Feb. 9, 1937. v. E. HEYwoob 2,070,205

MANUFACTURE OF WINDOW ENVELOPES Filed June 27, 1934 3 Sheets-Sheet 2 V A n w 4mm IIIIJJTJHIIIIHIIJ lnuenior Q Uincent 8.Heywood Feb. 9, 1937. v. E HEYWOOD MANUFACTURE OF WINDOW ENVELOPES Filed June 27, 1934 5 Sheets-Sheet 3 Patented Feb. 9, 1937 UNITED STATES PATENT QFFHQE MANUFACTURE OF WINDOW ENVELOPES Application June 27, 1934, Serial No. 732,716

7 Claims.

The present invention relates to the manufacture of window envelopes of the two-piece type, namely window envelopes characterized by substantially transparent panels or patches secured within the inside of the envelopes and covering openings formed in the front wall of the same.

In the previous manufacture of window envelopes of the two-piece type, it has been customary to employ either reciprocating pickers or rotatably mounted dies for applying adhesive to the areas surrounding the window openings in the envelope material, with the gum applying areas of such pickers, or dies, substantially corresponding to the areas of the panels or patches Subsequently applied to the window openings. However, it has been found that repeated gumming of the pickers or dies results in accumulation of the moist adhesive around the edges thereof, and the consequent building up effect ultimately causes overguinming of the areas surrounding the window openings. Thus, a stage is finally reached in the manufacture of the envelopes in which the patches do not entirely cover the gummed areas surrounding the window openings, and the excess gum extending beyond the boundaries of the applied window patches often causes adhesion between the front and rear walls of the completed envelopes. While it is possible to more or less nullify the effect of gum building up around the pickers by making the gummed areas less than the patch areas, such an expedient is undesirable, since it is then impossible for the patch to be completely adhered around the window openings. Furthermore, different sizes of pickers and dies have to be provided for making envelopes with different sizes of window openings.

According to the present invention, the above described undesirable results encountered with the employment of gumming pickers or dies are entirely avoided by employing a continuous surface of revolution to apply the adhesive around the window opening, with the result that there is no accumulation of adhesive on the gum applying surface. Furthermore, by controlling the duration of the engagement of the gumming applying surface of revolution with the envelope material, it is possible to apply gummed areas around window openings of different widths, with the length of the gummed areas determined by the length of the surface of revolution. The above and other advantageous features of the invention will here inafter more fully appear from the following description with reference to the accompanying drawings, in which:-

Fig. l is a vertical sectional View illustrating a window gurnming mechanism embodying the invention.

Fig. 2 is a fragmentary View, partially in section, along the line 2-2 of Fig. 1, and showing details of the gum applying mechanism.

Fig. 3 is a plan view of the cylinder on which the window gumming and patch applying operations are performed.

Fig. 4 is a fragmentary view illustrating the gearing for driving the gumming mechanism of Fig. 1.

Fig. 5 is a view in side elevation of the gearing shown in Fig. 4.

Fig. 6 is a fragmentary view illustrating a portion of the parts of Fig. l in a different position.

Fig. '7 is a fragmentary view illustrating the gumming of envelope material in web form.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, an envelope blank I is shown as being fed between guides 2 around the periphery of a cylinder 3 by means of segmental feed rolls 6 cooperating with an idler roll 5 and with the cylinder 3, respectively. The blank I provides a window opening 6, and the surface of the cylinder 3 carries a removable segmental platen 1, preferably of hard rubber, in the surface of which is formed a depression la of substantially the same size as the window opening 6. Blanks I are intermittently fed around the periphery of the cylinder 3 by the segmental feed rolls 4 at such a rate that as the cylinder 3 rotates, the platen depression lot will register with a window opening 6 of a blank I for each complete revolution of the cylinder 3.

A tub 8 containing liquid adhesive is suitably supported above the cylinder 3 and a roll 9 running in the tub continuously delivers a thin film of gum to the periphery of a second roll II] rotatably supported with its periphery extending below the bottom of the tub 8 and spaced from the periphery of the cylinder 3. A gumming roll it having a diameter considerably less than the distance between the peripheries of the cylinder 3 and roll I is freely mounted on a shaft 12 supported at its ends by arms I3 pivotally mounted on a shaft l4 carrying the feed roll 4. Since the shafts I2 and I4 extend parallel to shafts I and I6 carrying the cylinder 3 and the roll Ii] respectively, it follows that oscillatory movement of the gumming r011 II about its pivotal axis will serve to bring its periphery into tangential engagement with the periphery of either the cylinder 3 with its platen I, or the adhesive coated roll Ill.

In order to control the oscillatory movement of the gumming roll II, the ends of the shaft I2 are received in forks I! which embrace the cylinder shaft I5 and carry rolls I8 bearing on the surfaces of adjustable cams I9 mounted on the shaft I5, see Fig. 2. Therefore as the shaft I5 rotates, an oscillatory movement is imparted to the gumming roll II, and the cams I 9 are so timed that the gumming roll II is moved downwardly away from the roll ID to engage its gummed surface with the blank I a short interval prior to the registration of window opening 5 with the platen depression la. Shortly after registration of the window opening 6 with the platen depression Ea is completed, the gumming roll II is lifted out of contact with the blank, and as a result of this timed engagement of the adhesive covered surface of the roll II with the blank I, an area of gumming, shown by stippling, is applied to the blank around the window opening 6, the outlines of the blank being indicated by dot and. dash lines.

In view of the fact that the gumming roll II engages and leaves the moving blank appreciable distances away from the leading and following edges of the window opening 6, the gumming extends up to the edges of the window opening on all sides. Furthermore, since the cams I9 are symmetrical about the axis of the shaft I5, and since the roll H is centered with respect to the platen depression id, as is apparent from Figs. 2 and 3, it follows that the gumming applied to the blank extends uniformly on all sides of the window opening 6. Each cam I9 is formed in two parts, angularly adjustable, as indicated in Fig. 1, so by properly adjusting the cams I9 and choosing the length of the roll II, it is possible to apply an area of gumming around a window opening 6, the dimensions of which correspond exactly to the dimensions of a transparent patch or panel subsequently applied to the blank by suitable patch applying instrumentalities.

' ried by the cylinder 20 in the manner described For purposes of illustration, the patch applying instrumentalities are shown as comprising a cylinder 20 mounted on a shaft 2i parallel to the shaft IS, with a transparent patch 22 carin Furman Patent No. 1,428,429 issued September 5, 1922. In operation, the rotation of the cylinder 20 is so timed as to deliver one edge of the patch 22 to the cylinder 3 coincidentally with the arrival of one edge of the gummed blank area at the point of tangency of the cylinders 3 and 23. Thereafter, continued rotation of the cylinders 3 and 20 causes the patch 22 to be applied accurately to the gummed area of the blank surrounding the window opening 3, with the result that the gummed area is completely covered by the patch. The blank I with the patch 22 applied thereto is then transferred from the surface of cylinder 3 to the surface of a cylinder 23, which in cooperation with belts 26 and 25, serves to deliver the blank for operation upon by suitable folding instrumentalities, not shown,

. which convert the blank into a complete window envelope.

Referring now to Figs. 4 and 5, there is shown the gearing for driving the various elements of the previously described mechanism so as to accomplish the desired results. As shown. a drive shaft 26 is connected through bevel gears 2? to a shaft 28 carrying the cylinder 23. The shaft 28 is connected to the shafts I5 and 2i by gearing 23, so that the cylinders 3, 2E and 23 are all driven at the same speed. .The shaft I5 is also connected by gearing 30 to shaft I t carrying the feed roll 4, the shaft It being in turn connected by gearing 3i and countershaft 32 to the shafts of the rolls 9 and III which deliver adhesive to the gumming cylinder II.

In the operation of the mechanism, the blanks are delivered one by one between the guides 2 and rotation of the first segmental feed roll 4 projects the blank around the periphery of the cylinder 3 in cooperation with a guide 33 so that the blank is delivered between the second segmental feed roll 4 and the cylinder 3. At the time the blank is first engaged by the forward roll 4, the gumming roll I I is maintained by the cams I9 in engagement with the continuously rotating surface of the adhesive covered roll ID, as shown in Fig. 6. Therefore, the roll it is well covered with the gum when it is swung downwardly to engage the advancing blank 2. short interval in advance of registration of the leading edge of the window opening 3 with the platen depression Ia. After applying adhesive to the blank around the opening 5 to the extent determined by the cams E9, the gumming roll returns to the position of Fig. 6 in engagement with the roll it where it remains until the next succeeding blank is fed to the cylinder 3.

As the blank I continues around the cylinder 3, a patch 22 carried by the cylinder 23 is applied to the gummed area around the window opening 6, with the patch completely covering the gumming. The blank continues around the cylinder beneath a guide 34 and then around the cylinder 23 to the belts 24 and 25. Since in passing from the cylinder 3 to the cylinder the blank changes its direction of movement, the invention provides means for insuring that the blank will leave the surface of the cylinder 3 as its leading edge reaches a point of tangency with the cylinder 23.

As best shown in Fig. 1, the shaft I5 carries an arm 35 frictionally held in position on the shaft I 5 by means of a plunger 36 pressed against the shaft I5 by a spring 31. The pressure exerted by the spring 3'! is adjustable by means of a set screw 38 and the frictional engagement of the plunger 36 with the shaft I5 is such as to maintain the arm 35 in any predetermined angula-r position on the shaft I5. The opposite end of the arm 35 carries a pivot 39 on which is freely mounted a finger 4D, and with the arm 33 in the position of Fig. 1, the finger ll] is held by a pin ll received in a slot 42 in such a position that the free end of the finger lightly engages the leading edge of a blank. In order to permit angular adjustment of the arm 35 so as to position the finger where it will engage the leading edge of the blank, the cylinder 3 provides a slot 3a.

As the cylinder 3 turns with the shaft I5, the finger at the end of the arm 35 follows the leading edge of the blank and exerts a force tending to strip the blank from the cylinder 3 as the leading edge thereof approaches the periphery of the cylinder 23. The stripping action of the finger 40 is due to the fact that both gravity and centrifugal force tend to throw the finegr 40 toward the cylinder 23 as the finger reaches the lowermost point in its travel. Therefore, the leading edge of the blank is prevented from continuing around the surface of the cylinder 3 and is positively directed beneath a guide 43 around the surface of cylinder 23 into the bite between the belt 24 and the cylinder 23, as shown in Fig. 6.

From the foregoing, it is apparent that by the present invention there is provided an extremely effective and simple means for applying adhesive to areas surrounding the window openings of envelope blanks. The mechanism is particularly characterized by the application of the adhesive up to the edges of a window opening on all sides, with the area of the gumming surrounding the window opening exactly corresponding to the area of the patch subsequently applied thereto. By adjustment of the cams controlling the oscillatory movement of the gumming roll, it is possible to very accurately determine the Width of the gummed area around the window opening, with the length of the roll determining the exact length of the gummed area. By utilizing a rubber platen having an area equal to the face of the largest envelope to be made, it is possible to locate the depression in this platen at any desired point to correspond with the location of the window opening in the envelope face. While for purposes of illustration an envelope blank is shown as being operated upon by the mechanism in Fig. 1, it is obvious that a continuous web of envelope material can be conveyed around the platen cylinder, as indicated in dotted lines in Fig. 5, without altering the mechanism. A portion of such a web is illustrated in Fig. 7, the web being provided with window openings so spaced that the leading edge of an opening will register with the leading edge of the platen depression on the cylinder for each revolution of the platen cylinder.

I claim,

1. A step in the manufacture of window envelopes which consists in advancing envelope material having a window opening therein and applying adhesive to an area completely surrounding said opening by positively controlling the duration of the rolling contact of a gummed surface of revolution with said material.

2. A step in the manufacture of window envelopes which consists in advancing envelope material having a window opening therein and applying adhesive by positively controlling the duration of the rolling contact of a gummed surface of revolution engaging and leaving the moving envelope material appreciable distances away from the leading and following edges of the window opening.

3. A step in the manufacture of window envelopes which consists in advancing envelope material having a window opening therein and applying adhesive by positively controlling the duration of the rolling contact of a gummed surface of revolution engaging the envelope material and passing over the window opening to apply an area of adhesive completely surrounding said opening.

4. Apparatus for the manufacture of window envelopes, comprising a surface of revolution for supporting envelope material having a window opening therein, said surface of revolution carry ing a rubber inset having a depression adapted to register with the window opening as the material passes around the surface of revolution.

5. In mechanism for applying adhesive around the window opening of a moving envelope blank, a cylindrical roller forming a part of a gum mixing and distributing train of rollers, and means for bringing said roller into rolling contact with a moving envelope blank, for applying an area of gum determined by the length of said roller and the duration of its contact with said blank.

6. In mechanism for applying adhesive around the window opening of a moving envelope blank, a complete cylindrical roller ordinarily forming a part of a train of gum distributing and mixing rollers, but capable of being removed from said relation and brought into rolling contact with a moving window envelope blank for a space of time wherein the blank moves the distance equal to the length of gummed area, said area being determined in one. dimension by the effective length of said roller and the other dimension by the duration of contact.

7. Apparatus for the manufacture of window envelopes, comprising means for advancing envelope material having a window opening therein, a gumming element adapted to oscillate between a supply of adhesive and the moving surface of said envelope material for applying adhesive around a window opening by rolling contact, and means for causing said gumming element to engage and leave the moving envelope material at predetermined distances away from the leading and following edges of a window opening.

VINCENT E. HEYWOOD. 

